This invention relates to a process and apparatus for conducting distillation and/or stripping in a column of the type wherein the lower portion or sump of the column is heated and the upper portion or head is cooled, and with the heating and cooling means interconnected and operatively coupled with each other by means of a heat pump system. Such processes and apparatus are well known and described many times in text books as well as in journals, e.g. Chem Eng. Sept. 26, 1977, pages 78 to 86.
It is known that introducing a stripping gas or vapor to the lower portion of a column lowers the partial pressure within the column and simultaneously reduces the temperature in the column. This effect thus created is often utilized for the careful separation of materials or substances by distillation, as well as for the regenerating by stripping of a scrubbing agent in various chemical and physical washing operations. As the stripping gas or vapour, steam is often utilized to provide special advantages in such operations. More particularly, the steam can either be blown directly into the sump of the column, during distillation or stripping, or, if the column feed initially contains water, it can be generated by external heating of the column sump. Occasionally, both uses of the steam are combined. In these processes, the sump heater and the head cooler of the column can be connected and operatively coupled with each other in a conventional manner by means of a heat pump arrangement.